Low pressure blowout preventer



July 1, 1958 A. s. BADGER LOW PRESSURE BLOWOUT PREVENTER Filed June 23,1955 2 Sheets-Sheet 1 INVENTOR.

ALGERNON S. BADGER,

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July 1, 1958 A. s. BADGER LOW PRESSURE BLOWOUT PREVENTER 2 Sheets-Sheet2 Filed June 23, 1955 FBG. 4A.-

INVENTOR. ALGERNON s. BADGER,

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United States Patent Ofifice 2,841,422 Patented July 1, 195's LOWPRESSURE BLOWOUT PREVENTER Algernon S. Badger, Houston, Tex., assignor,by mesne assignments, to Esso Research and Engineering Company,Elizabeth, N. 1., a corporation of Delaware Application June 23, 1955,Serial No. 517,473

6 Claims. (Cl. 286-165) The present invention is directed to an improvedlow pressure blowout preventer for controlling the pressures encounteredduring the operation of drilling a well. More specifically, the presentinvention is directed to a blowout preventer in which the sealing meansis a deformable sleeve positioned in and fixed to a housing which isattached to the top of a casing such as surface casing which haspreviously been cemented in place in the ground. v

The purpose of the present invention is to form a positive seal around adrill pipe extending through the device and therefore close off theannulus between the casing or borehole and the drill pipe. This purposeis suitably accomplished by forming on the inner surface of thedeformable sleeve a series of projections or serrations that willoverlap and interlock with one another and fill any voids or Openingscaused by crimping of the sleeve when the sleeve is forced against thedrill pipe which is of a substantial smaller diameter than thedeformable sleeve.

In a blowout preventer where a sleeve-type sealing member is used toseal around the drill pipe, the sleeve has to be large enough in itsundeformed position to allow a drill bit, for example a 9%" bit, to passthrough and when pressure is applied to the outer Wall of the sleeve toseal around the drill pipe, such as a 4 /2" outside diameter pipe. Thesleeve, if it has a constant or smooth inside diameter, will crimp orform folds upon coming in contact with the pipe.

These folds or crimping of the rubber sleeve form openings or slitsbetween the sleeve and the pipe and, therefore, do not provide apositive seal around the drill pipe.

The present invention has overcome this disadvantage as will be seen inthe description taken in conjunction with the drawings in which:

Fig. 1 is an elevation, partly in section, illustrating the device ofthe present invention attached to the top of a surface casing duringdrilling operation;

Fig. 2 is an enlarged sectional view of the device of Fig. 1;

Fig. 3 illustrates the sleeve member of the device in sealingrelationship with the drill pipe;

Fig. 4A is a sectional view of the deformable sleeve member of thepresent invention in the undeformed position;

Figs. 43 and 4C are sectional views showing the shapes assumed by thedeformable sleeve when partially and fully expanded about a section ofpipe;

, Fig. 4D is an enlarged fragmentary sectional view taken along the line4d4d of Fig. 4C;

Fig. 5 (Sheet 1) is an enlarged fragmentary sectional view of the deviceof Figs. 1 and 2;

Fig. 6 is a sectional view taken along the line 66 of Fig. 5;

Fig. 7 is a showing of another embodiment of the sleeve member of Figs.1 through 5;

Fig. 8 is a top view of Fig. 7;

Fig. 9 is a top view of another embodiment of a sleeve member;

Fig. 10 is a sectional view taken along the line 10-10 of Fig. 9; and

Fig. 11 is a showing of still another embodiment of a deformable sleevemember.

Turning now to the drawings and especially to Figs. 1 through 6, numeral11 designates a housing which is attached to a surface casing 12 bymeans such as a flange member 13 and bolts 14.

Concentrically positioned in housing 11 and fixed to the upper and lowerends of the housing 11 by clamping rings 15 and clamp bolts 16 is adeformable sleeve member 20. Enclosed by and extending through housing11 and casing 12 is a drill pipe 8.

Sleeve member 20 forms at its upper end and its lower end annularshoulders 21 by which the sleeve 20 is secured to the housing 11 byclamping rings 15.

The Wall of the housing 11 and the sleeve 20 form a pressure-tightannulus or chamber 22. Housing 11 is also provided with a threaded inlet23 to which is attached by a screw fitting 24 a pressure hose or conduit25.

Conduit 25 is attached to a pressure source such as an air compressornot shown.

When it is desired to seal around the drill pipe 8, such as when excessformation pressures are encountered, pressure is applied to the chamberor annulus 22, therefore squeezing the deformable sleeve 20 around thedrill pipe 8 and sealing of the casing annulus below the sleeve member20 as illustrated in Fig. 3. A possible first position and 'a closedposition taken by the deformable sleeve member 20 upon applying pressureto the chamber 22 are illustrated in Figs. 4B and 4C. It may beunderstood that sleeve 20 may assume any of several positions or shapesupon contacting the pipe 8.

Turning now to Figs. 5 and 6, the sleeve member 20 is reinforced at itsclamping ends by reinforcing means 26 such as cord or fabric which maybe nylon ribbons and the like embedded in and vulcanized to the rubber.These reinforcing members are embedded in the annular shoulders 21 andalso extend a substantial distance into the wall of the sleeve member20. This allows a stiffening and strengthening effect for clamping ofthe sleeve to the housing.

Sleeve member 20 is also provided with a plurality of verticallyextending reinforcing members shown as short lengths of cable 27 whichare also embedded in the wall of the sleeve 20 and equally spaced apartin the wall of the sleeve 20.

The inner surface of the sleeve 20 defines at a point midway between itsupper and lower ends a plurality of inwardly projecting annularserrations or saw tooth projections 28. These serrations are shown astriangular in cross section but may be formed in various patterns asdesired.

The serrations or projections 28 form part of the inner wall of thesleeve member 29 but are of a more pliable consistency than the rest ofthe sleeve 20. The serrations 28, being of a softer or more pliablenature than the rest of the sleeve member, have a tendency to besqueezed or mashed out more readily when coming into contact with thepipe and overlapping and interlocking with one another, thereforefilling up any cracks or openings formed by folding or crimping thesleeve member 20 when it contacts the pipe as is illustrated moreclearly in Figs. 3 to 4C. Figs. 4B and 4C illustrate one of a number ofpositions that the deformable sleeve 20 may assume when fluid pressureis applied to the chamber 20.

As shown in Fig. 4B, the sleeve 20 has contacted the pipe 8 at threepoints and has assumed a crosssectional triangular configuration andleaving openings such as a, b, and c between the sleeve 20 andthe. pipe8.

As more pressure is applied to chamber 22, the Walls forming theopenings at, bpand c are folded together until they assume the positionasshownjin Fig. 4C. The serrations 28 of the walls upon beingclosedftogether,

being somewhat triangular in cross-section and having rather sharp'crests, tend: to slip somewhat and overlap and interlock with oneanother. The serrations 28., being also. of a softer or more pliablecomposition: than the wall of the sleeve20, are mashed together andagainst the pipe 8 and, therefore, completely close any opening betweenthe sleeve 20 and the. pipe 8 in the first folded positioni.

The sleeve 2!} may, upon being pressurized, initially.

contact. the pipe 8 at two or maybefour points and, if so, the openingsformed, such as shown in Fig. 4B, are closed in the same manner asdescribed.

The embodiment of Figs. 7 and 8 shows a sleeve member 30 provided withtwospaced-apart sets of annular internally projecting serrations 31. Inthis embodia adapted to seal off a well bore comprising, in combination,

a housingwadapted to be connected into a surface casing in said wellbore and having a vertical axial opening therethrough, a deformablesleeve member arranged in said housing concentric to said axial openingwhereby a fluid-tight annular chamber is formed between the inner Wallof said housing and the outer wall of said sleeve member, said housingbeingprovided with a fluid'inlet communicating with said fluid-tightannular chamber,

merit .the wall of the sleeve member 3% is reinforced 7 immediatelyabove and below the serrations 31 by reinforced means 32 such as fabricwhich may be nylon or the like.

The embodiment of Figs. 9 and 10 shows a deformable sleeve member 4%)provided with equally spaced-apart sets, of vertically extendingserrations 41a, 41b, and .410. This embodiment, as in Figs. 7 and 8, isalso provided with reinforcingtmeans 42 which are'embedded 'in the wallof the sleeve member 40 immediately above and I below' the serrations.It. will be understood that the Sleevev 46 of Figs. 9 and 10 is formedso that when it is pressurized it folds around a pipe arranged thereinsuch that serrations 41a come together, as do serrations 41b andlc' andseal the slits formed by the sleeve as previously explained.

Fig; ll is similar to the showing of Figs. 9' and 10 but with thevertical serrations equally spaced apart.

Having fully describedand illustrated the present invention, whatIclaimis: V a

"1. A device for controlling pressures ina well and said deformablesleeve member having formed .on its inner wall a plurality of inwardlyprojectingannular serrations, said wall ofsaid deformable sleeve memberbeing internally reinforced adjacent said serrations and at each of itsends, saiddeformable-sleeve member having a non-deformed positionwhereby said vertical axial opening is unobstructed and a maximumdeformed position whereby said axial opening is completely closed.

2. A device in accordance with claim 1 in which the continuous inwardlyprojecting annular serrations; are

formed. of; a more pliable composition than said :wall of saiddeformable sleeve member. I v i 3. A device for controlling pressures ina well and adapted to seal off a well bore comprising in combination atubular housing adapted to be connected into a surface casing in saidwell bore, a deformable sleeve member having an opening therethroughmounted in said housing.

and forming with said housing a pressure-tight annular chamber,saidthousing being formed t'o'provide a fluid inlet; communicating: withsaid annular chamber, said sleeve member being provided with a pluralityof'internally proiectingserrations on its inner Wall intermediate itsupper and lower ends, said serrations being of a greater deformabilitythan said sleeve member whereby 1 when said annular chamber ispressurized said sleeve .is

deformed and the opening: through said sleeve is sealed. 4. A device inaccordance with claim 3 in. which said deformable sleeve member isinternally reinforced at each end and adjacent said serrations.

51A device in accordance with claim 4 in which the internally projectingserrations are annularly extending.

6; A device; in accordance withdclaim 4 in which the inwardly projectingserrations are spaced apart and vertically extending.

References Cited in the file of this patent- V UNITED" STATES PATENTS1,930,361 1,942,366 Seamark Jan.'2, 1934 2,258,887 Fortune Oct. 14, 19412,306,160

Kilmer Oct. 10,1933

7 Freyssinet Dec. 22, 1-942

